This invention relates to disposable diapers having elasticized leg openings, and more particularly to an improved side closure for such disposable diapers. Still more particularly, this invention relates to an improved side closure for disposable diapers having elasticized leg openings comprising an outer fastening means and an inner fastening means.
Disposable diapers are well known articles of manufacture which are worn by infants and incontinent persons. Disposable diapers are worn about the lower torso and are intended to absorb and contain urine and feces thereby preventing the urine and feces from soiling, wetting, or otherwise contaminating the articles (e.g., clothing, bedding, etc.) which come into contact with the diaper wearer.
In general, disposable diapers all have the same basic structure which comprises an absorbent core encased between a liquid permeable user contacting topsheet and a liquid impermeable backsheet. The prior art, of course, teaches numerous variations of and elements in addition to the basic topsheet, backsheet, and absorbent core arrangement. For example, an improvement in the performance of disposable diapers has been achieved by the addition of an elastic means along that portion of the disposable diaper which contacts the wearer's thigh thereby providing elasticized leg openings when the diaper is worn.
When using a disposable diaper having elasticized leg openings the diaper user fits the diaper on the wearer and fastens it about the wearer's waist thereby effecting a side closure. Fitting the diaper about the wearer usually requires the front and back waist portions of the diaper to overlap each other. As the diaper is worn the movements of the wearer and the forces induced by the elastic means at the leg openings tend to cause the overlapping front and back waist portions to shift position relative to each other. In other words, overlapping front and back waist portions are subjected to forces which tend to cause the front and back waist portions to assume a position relative to each other which is different from the position they assume when the diaper is initially fitted to the wearer. Unless such shifting is limited the fit and containment characteristics of the diaper are degraded as the diaper is worn.
A number of concepts have been proposed for fastening a disposable diaper about the waist of the wearer. For example, U.S. Pat. No. 3,848,594, which issued to K. B. Buell on Nov. 19, 1974, teaches a tape fastening system for effecting a side closure in disposable diapers which has an improved manufacturers joint (i.e., the attachment between the fastener tape and the diaper which is made by the manufacturer). U.S. Pat. Nos. 3,359,980 which issued to C. L. Rosenblatt on Dec. 26, 1967 and 3,638,651 which issued to D. Torr on Feb. 1, 1972 both teach diapers in which a side closure is effected by overlapping portions of the diaper. Additional side closures are described in U.S. Pat. Nos. 3,776,232 which issued to C. H. Schaar on Dec. 4, 1973 and 4,122,552 which issued to F. Tedford on Oct. 31, 1978. Both the Tedford and Schaar patents are directed to improving the side closure by affixing the front and back waist portions together over a relatively large area. The Schaar patent achieves this result by using two fastening mechanisms while the Tedford patent uses a single fastening system which covers a relatively large area.
None of the foregoing patents are specifically directed to disposable diapers having elasticized leg openings and the special problems of maintaining good fit characteristics associated with such diapers. U.S. Pat. No. 4,253,461 which issued to D. L. Strickland et al. on Mar. 3, 1981, is directed to a disposable diaper having elasticized leg openings and achieves an improved side closure by providing separate fastening means at the waist and at the thigh.
The disposable diapers of the prior art lack the aspects of the present invention whereby an improved side closure having an outer fastening means and an inner fastening means is provided which means together prevent relative motion between the front and back waist portions.
It is therefore an object of the present invention to provide an improved side closure for disposable diaper having elasticized leg openings.
A further object of the present invention is to provide an improved side closure which maintains the fit of the diaper at the waist and at the elasticized leg openings during wearing.
An additional object of the invention is to provide a disposable diaper having elasticized leg openings which has improved urine and feces containment characteristics.
These and other objects of the invention will be more readily apparent when considered in reference to the following description and when taken in connection with the accompanying drawings.